The immediate goal of this research is to acquire information about the operation of binocular rivalry, with special emphasis being placed on the suppression process. The data define basic empirical characteristics of rivalry and serve to test assumptions of reasonable alternative models of rivalry. The general experimental technique utilizes the psychophysical paradigm whereby considerable data are obtained from a small number of trained observers. In many specific experiments test-probe stimuli are used to specify parameters of the suppression state. Previous work has revealed that during phases of phenomenal suppression there is a general inhibition of the retinal region containing the suppressed target. The implications of these and other data are used to provide guidelines for further inquiry. The long-range objective is to contribute to a general theory of binocular vision that would encompass rivalry, stereopsis, and fusion within a unitary framework. Further, the research should bear upon the problem of strabismic amblyopia and upon the mechanisms of attention.